What to do for observing Sirius

 This diagram shows the 50-year-long orbit of Sirius B around Sirius (called Sirius A). The scale is in "arc seconds". One arc second is equal to 1/1800 the diameter of the full moon. Credit: FrancesoA

•  Astro Bob

 What to do for observing Sirius
- Wayne Mitchell (Star Gazer's Deep Space Atlas )

Someone there hopefully a 12 or larger scope? The one I use is a 12 Dobsonian FL=1500 F4.9. So focus is very sensitive. I think a 12 Cassegrain would probably be better because of a longer FL and more play with focus.

Wait until just has just set. Sirius must be the first star visible. DO NOT wait until dark, you will not see Sirius B when dark because glare of parent star too bright (well I haven't been able to). 

At present, Sirius is overhead at this time of year which is important because you look through less atmosphere.

IMPORTANT; there must be some thin cloud, favorably uniformly spread. This acts as a good glare filter for the parent star, but is not enough to dim the light from Sirius B too much. In saying this I wonder if you will have any this cloud there at all?

Then, at least 200X magnification will work. I only use 200X because do not have eyepiece for higher power, but it works.

Advance the scope slightly ahead of the star so that when you view the star the telescope is steady and allow the star to drift through the field of view of your eyepiece. Slight vibration will inhibit your view of Sirius B.

With these conditions, you still need stable air. While looking into the eyepiece, stare slightly into the glare of the parent star. Sirius B may momentarily pop out of the glare and disappear again. It is extremely tiny!

It is still a challenge, but these conditions aid significantly.

Try this for a few minutes, dont give up too quickly.

If you still do not see Sirius B, rotate the base of your telescope by 45 degrees. By doing this, you may be moving Sirius B out of the bright diffraction spike caused by the parent star. If Sirius B is aligned with a diffraction spike you wont see it.

Try again.

Hope this helps

Regards

Wayne

Die Melkweg

Wayne Mitchell stuur vir ons hierdie een op Idees vol Vrees se facebook-blad

Besoek gerus Wayne se  webblad - Star Gazer's Deep Space Atlas

2012 Karoo Starparty

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Karoo Starparty, 21 - 25 Maart 2012

The ASSA Pretoria Centre is continuing the annual National Karoo Starparty which was started in 2009 at the Kambro Padstal, about 20 km north of Britstown in the Karoo, next to the N12 NationalRoad.

This event is intended to be a get-together for friends that want to enjoy the beautiful Karoo sky and there are no scheduled events, talks or workshops – we go there simply to enjoy the company of fellow stargazers and the legendary Karoo sky. The date for the 2012 Starparty is scheduled for the week-end of 21 March 2012. That is Wednesday 21 to Sunday 25 March 2012.

Wednesday 21 March is a National Holiday. Please book early to avoid dissappointment!

• See Kambro Accommodation or phone Wilma Strauss at 0833056668 for details of the site and to make a booking.
  
  
• There is also accommodation available in Britstown at the Karoo Country Inn.

Information about the Karoo Starparty. GPS Co-ordinates: S30°-25-00.3    E23°-33-56.1 Complete Darkness 21 March Dark from 19:50 - 05:10 22 March Dark from 19:54 - 05:11 23 March Dark from 19:53 - 05:12 24 March Dark from 19:51 - 05:13 Deepsky Observing Lists (Karoo Star Party) 23 March 2012, Pdf format, Created with Skytools 3 Sorted by Constellations SA: Sky Atlas 2000 Chart UR.2: Uranometria 2nd Edition Chart PSA: Pocket Sky Atlas (Sky and Telescope) - ASSA Top 100 (telescope) - Concards (Constellation Cards) - Bennett - Herschel 400  - Messier - UHC-filter objects - OIII-filter objects - Binocular objects - How to find the South Celestial Pole (SCP) almost accurately. - Weather    Southern hemisphere Jetstream    Britstown, Northern Cape  Accuweather    Britstown, Northern Cape Yr.No

More Starparty links

• Pretoria Centre of the Astronomical Society of Southern Africa - Karoo Starparty 2012
  
• Kambro Starparty
  
• History of the Karoo Star Party
  Star Party Karoo April 2009 - Photos on Flickr
  
• Karoo National Star Party, Britstown, 2010 August 06-09  By Richard Ford

• 2010 Karoo Star Party - photos
  
• 2011 Karoo Star Party
  
  
• 2011 - Karoo Starparty photos

Groot Magellaanse Wolk vanaf Boyden-sterrewag

Hi Almal, hier is een van die fotos wat geneem is tydens die naweek van die Bloemfontein/Johannesburg inter. Die een is Vrydagaandgeneem.

Frans Human het sy Canon kamera en 200mm f2.8 lens saamgebring en saam kon ons hierdie foto saamstel.

Dit is slegs 'n uur se data in totaal. Die tarantula lê links onder in die wolk. Hy vertoon blou en nie pienk nie, omdat die DSLR kamera 'n ingeboude infra rooi filter het wat dan maak dat die chip baie onsensitief vir die rooi in waterstofnewels is.

Die GMW bestaan uit ongeveer 10biljoen sterre.

Dit is verstommend hoe baie sterre die agtergrond alleen uitmaak en dis nie eers deel van die melkweg nie.

Groete

Brett du Preez

Klein Magellaanse Wolk vanaf Boyden-sterrewag

Hier het Brett du Preez van ASSA Bloemfontein die  Klein Magellaanse Wolk in Tucana met `n Canon DSLR op `n volgmopntering vasgevang. NGC 104 (Tucanae 47)  is duidelik sigbaar. Ook NGC 362, `n effens kleiner bolvormige sterreswerm is net links van die Klein Magellaanse wolk sigbaar. (200mm lens @f2.8, Canon DSLR ISO 800)

• Die foto is tydens ASSA Johannesburg se besoek aan Bloemfontein geneem.

M45 vanaf Boyden-sterrewag

Brett du Preez van ASSA Bloemfontein het M45  (Pleiades) in swart-en-wit vasgevang. Van die beligtings is einde 2011 gemaak en toe nog `n paar vroeg in die nuwe jaar.

Komeet Lovejoy op 1 Januarie 2012

Foto: Hannes Pieterse (Klik om foto te vegroot)

 Uiteindelik kon ek ook vir komeet Lovejoy sien. Die wolke het Nuwejaarsnag in die niet verdwyn en so in die deinserigheid oor die see by  Reebok het ek so 03:00 na die wasigheid begin soek. Eers niks, maar toe het ek die stert se kante as `n skerp lyn met 'n verkyker (12 X 50) gesien. Dof maar daar. Die ligbesoedeling is nogal `n probleem - Die son wat amper opkom en die ligte van Mosselbaai.  By `n lekker donker plek sal mens die komeet dalk met die blote oog kan waarneem. Nie hier oor die see nie.

Selfs op die foto is die komeet baie dof. Kyk mooi. Dit kern is net buite Ara en dan loop dit reg deur Triangulum Australe.(Op die nuwe verwerkte foto is die komeet baie dudieliker)

Oor 'n paar dae gaan die komeet reeds vroegaand sigbaar wees. Dit moet baie donker wees.

Fotoinligting: Canon 30D op driepoot gemonteer; fokale lengte: 17mm x1.6; 3 minute beligting; f6.3; ISO 800; Foto baie effens met Lightroom verwerk. Finale verwerking met Neil Carboni se Astronomy Tools in Photoshop.

Groete
Hannes Pieterse

(Comet Lovejoy)

Kepler 22b - the 'new Earth' - could have oceans and continents, scientists claim

Kepler 22b, the planet which scientists say hold the best hope yet for future human habitation, could have continents, oceans and creatures already living on its surface, they believe. 

 The new planet was discovered by Nasa’s Kepler space telescope two years ago but new research has identified it as the most similar to our own yet discovered.

Kepler 22b is about twice the size of Earth and has temperatures which average around 72 degrees (22 Celsius).

It also contains the right atmosphere to potentially support life. However, there is a downside: it is 600 light years from Earth.

Kepler 22b is the first so-called "super-Earth" known to lie within the "habitable" zone of a star similar to our Sun.

Dubbed the "Goldilocks Zone", this is the band where temperatures are just right to allow the existence of surface liquid water throughout its orbit. 

• Read more

No Hope for the Russian Space Probe

The European Space Agency has given up on efforts to revive Fobos-Grunt, the Russian space probe that was slated to visit the Martian moon Phobos, but got stuck in Earth’s orbit shortly after launch.

The unmanned probe was launched on Nov. 9 with a mission to take soil samples from the Martian moon and fly them to Earth. All efforts from the ESA to send the probe commands that could send it to the next stage of its mission have been unsuccessful, however, and now the ESA has announced it will not be making further attempts to contact the probe. 

“In consultation and agreement with Phobos-Grunt mission managers, ESA engineers will end tracking support. Efforts to send commands to and receive data from the Russian Mars mission via ESA ground stations have not succeeded; no response has been seen from the satellite. ESA teams remain available to assist the Phobos-Grunt mission if indicated by any change in the situation,” said ESA in an official statement.

This likely won’t be the last we hear of the 13.2-ton spacecraft, as scientists expect it to fall back to Earth sometime in January. Most of its weight consists of highly toxic hydrazine and nitrogen tetroxide fuel, which, according to NASA veteran James Oberg, makes the probe the “most toxic falling satellite ever.”

If the fuel has frozen in space, some of it could survive the fall to Earth, but if it’s liquid, it will probably burn away – along with the rest of the probe – when re-entering the atmosphere, experts say. 

Source: Mashable Tech

Astronomy Magazine - Top 10 space stories in 2011

1.  The last flight of the space shuttle

2.  These standard candles aren't so standard - Some cepheid variables in dispute.

3.  Most eart-like planet found... yes, no, yes?

4.  Scientists watch as a black hole eats a star.

5.  Water may still flow on Mars.

6.  A Better understanding of the complexities of our star.

7.  An asteroid sharing Earth's orbit.

8.  The Milky Way blows bubbles - Gamma ray bubbles perpendicular to Milky Ways disk discovered.

9.  New type of stellar explosion - Supernova 2005ap in Coma Berenices.

10. Mercury reveals itself. Spacecraft Messenger imaged the surface after a journey of 7 years.

• Read these stories in the January edition.